1. Field of the Invention
The invention relates to an adjustable swimming pool floor system. In addition, the invention relates to a swimming pool comprising such an adjustable pool floor system. Furthermore, the invention relates to a method for installing the hydraulic system in a swimming pool. The invention also relates to a hydraulic system for use in an adjustable swimming pool floor system.
2. Description of the Related Art
Systems to adjust the height of pool floor in a swimming pool come in many varieties. One example is a scissor system that pulls and pushes the pool floor for obtaining respectively a deeper or shallower swimming pool. Another example is a pull system that uses chains or cables and winches to lift and lower a pool floor to obtain the desired depth.
A further example is a system that uses a buoyant pool floor that needs to be pulled downward to obtain a greater depth and is released to obtain a shallower depth. For such a system chains or cables connected to winches may be used to wind down the floor.
Another possibility is to use a hydraulic system to pull the cables or chains for lowering the pool floor. Such a hydraulic system is described in the European patent publication EP0532079. This document describes a swimming pool with an adjustable intermediate floor which has its own buoyancy. At the underside of the pool floor intermediate floor cables are fastened, which cables run by means of pulleys on the pool bottom to a hydraulic movement mechanism, with the aid of which the intermediate floor can be pulled under the water surface and held at a desired position. The cylinder barrels of the hydraulic cylinders of the hydraulic movement mechanism are arranged, sealed and slideably through a vertical wall of the pool near its bottom. The piston rods are fixed outside the pool, and the ends of the cylinder barrels project into the pool, each bearing a pulley head for the cables.
A disadvantage of this hydraulic movement system is that the cylinder barrel, which contains hydraulic fluid, usually oil, extends into the actual pool. If the cylinder barrel is defective, oil may leak into the pool water, thereby contaminating the water such that it is not suitable for swimming. In addition, the oil may cling to parts of the swimming pool in contact with the contaminated water including filters, pumps and other system components. Cleaning the water and in addition the contaminated parts is tedious work and may require considerable time and expense.
Another disadvantage of locating the cylinder within the pool is that access to the cylinder is complicated. Installation, servicing and replacement of parts of the system provided on or in the cylinder is difficult without removing the full installation—often requiring draining of the pool.
A further disadvantage is that due to the sliding of the cylinder barrel in the wall opening, safety devices to prevent the hydraulic system from becoming overloaded, especially the hydraulic cylinder, are difficult to install adjacent to the cylinder barrel.
It would therefore be desirable to provide an alternative hydraulic system that alleviates at least some of the perceived inconveniences of the prior art.